Specifications often state that glossy surfaces must be dulled before overcoating. What are some methods for doing this, especially when sanding isn’t feasible or desirable?

From
Tom Selby of Rodda Paint Corporation on
August 31, 2011: When a glossy surface cannot be sanded or mechanically de-glossed, I have had good results with cleaning the surface per SSPC-SP 1 and applying a bonding primer, such as Carboline's RustBond or Carbocrylic 120 waterborne, depending on the topcoat and the environment the coatings are placed in.

From
MOHAMED ZAKY ABU BAKAR of MINDUS (M) SDN BHD on
September 8, 2011:What about spraying the surface with an etching primer?

From
Lee Edelman on
September 1, 2011: Always try to overcoat before the window expires. If the surfaces to be coated are existing coatings, a bonding primer can be used if the systems are compatible and specification allows. The desired prep should produce a scarified surface for adhesion of the coatings. If sanding isn't feasible due to the dust generated, a slurry blast can also be considered. This method reduces suspended particles considerably.

From
Donald Powers of DJ Powers Paint Inspections on
August 30, 2011:If a glossy surface cannot be sanded or mechanically de-glossed, a sure-fire way is to wipe the surface down with trisodium phosphate (TSP), then rinse and let dry prior to coating application.